I'm curious to what makes you think there is a chance of a comeback?
Recycling is part of the "order to the disorder"... . That doesn't mean it will happen in your case and doesn't mean it should happen.
My thoughts were twofold... .
1.) Be ready for a recycle attempt... .being ready is where I was going with looking at tools. Especially since you have a letter and are considering a response.
2.) Possibly more important that 1. To be clear about is a recycle something you want. If you come to the conclusion that you do NOT want a recycle... .the actions from the lessons will be vastly different (yet no less important) than if you come to the conclusion that you are interested in a recycle.
Listen... .this is the staying board... .so you will get lots of advice here about staying... .about how to make it work. If in the process of your thinking you are really up in the air... .might be good for you to check out Undecided and see what guidance you can get there.
There are lots of ways that BPD family can help.
Last: Facebook and other small gestures are just that... small gestures... .tactical decisions. I would not read too much into that... .or spend much time thinking about that.